Rhodamine User Manual.pdf

Rhodamine WT Sensor
Instruction Sheet
00722789
Safety Precautions
Please read this entire instruction sheet before operating this sensor. Pay particular attention
to all danger and caution statements. Failure to do so could result in serious injury to the
operator or damage to the sensor.
Do not use or install this sensor in any manner other than that which is specified in this
instruction sheet.
Use of Hazard Information
If multiple hazards exist, this instruction sheet will use the signal word (Danger, Caution, Note)
corresponding to the greatest hazard.
DANGER
Indicates a potentially or imminently hazardous situation which, if not avoided, could
result in death or serious injury.
CAUTION
Indicates a potentially hazardous situation that may result in minor or moderate injury
or instrument damage.
Note: Information that requires special emphasis.
Precautionary Labels
Read all labels and tags attached to the instrument. Personal injury or damage to the
instrument could occur if not observed.
This symbol, if noted on the instrument, references the instruction sheet for operational
and/or safety information.
Introduction
The Rhodamine WT sensor is available as an option on the
DS5, DS5X, or MS5. The sensor is an in-situ optical
fluorometer that determines rhodamine concentration in a
given water sample. The sample is irradiated using green
(550 nm) light. The Rhodamine WT sensor absorbs the green
light energy and fluoresces or emits red (590–715 nm) light.
The sensor directly measures the amount of red light emitted by the rhodamine in the water
sample. The multiprobe can either display the rhodamine signal as a scaled voltage from
0–5 V or as a concentration from 0–1000 ppb.
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Rhodamine WT Sensor
Maintenance
Important Note: Do not use organic solvent solutions such as acetone or methanol with
the Rhodamine WT sensor. These solvents will damage the plastic housing cap.
The Rhodamine WT sensor requires periodic maintenance to remove contaminants such
as oil, biological growth, dirt, etc. Sensor maintenance should be conducted after every
deployment cycle, adjusting the deployment cycle length to account for the degree of
fouling that occurs in the area. Maintenance should also be done before and
after calibration.
1. Flush the entire instrument with clean fresh water. Use soapy water and a soft brush
to clean the outside surfaces of the instrument.
2. Soak the entire instrument in freshwater for at least 30 minutes.
3. Visually inspect the optical windows. Use optical tissue or a cotton swab with soapy
water to clean the optical windows. Rinse with freshwater.
Parameter Setup
Important Note: The Rhodamine WT sensor has been characterized at the factory to
display linear behavior between the gain zones. DO NOT change the values stored in the
Sensor Setup tab. This may result in non-linear readings.
The Rhodamine WT sensor functions using one of three gain settings:
• X1 gain provides a range of 0 to 1000 ppb
• X10 gain provides a range of 0 to 100 ppb
• X100 gain provides a range of 0 to 10 ppb
The factory-default will automatically switch the gain as needed. If necessary, the gain
settings may be fixed to one of the three gain settings described above.
1. Connect the sensor to a PC.
Note: If a Hydrolab Surveyor is used to display the voltage in the X10 or X100 fixed gain settings or
if the user changes the gain settings, then the Surveyor may require a RESET:HISTORY reset in
order to display the proper resolution.
2. Start Hydras 3LT. Wait for Hydras 3LT to establish communications with the sensor.
Click the OPERATE SONDE button.
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Rhodamine WT Sensor
3. Click the Parameter Setup tab and select Rhodamine ppb.
4. To enable auto gain, enter zero. To enable a fixed gain, enter 1 for X1, 10 for X10, or
100 for X100. In most cases, it is recommended to leave the sensor in auto gain mode
for maximum dynamic range.
5. Click the SAVE SETTINGS button.
Rhodamine WT Sensor Calibration
Rhodamine concentration is associated with an output voltage. This output voltage from
the sensor may be displayed directly or scaled to reflect a user-defined concentration
in ppb.
There are two standard methods for calibrating the Rhodamine WT sensor. Each method
requires a 2-point calibration. The first point must be 0 ppb. The second point should be a
non-zero value which is at least three times larger than the zero sample but within the
linear range of the sensor. It is recommended that the non-zero sample represents an
average or approximately 50% of the range of concentration the user expects to monitor.
A Solid Standard is recommended for defining repeated non-zero samples.
Method 1
Use this method when a known calibration standard is applied to the sensor.
1. Connect the sensor to a PC.
2. Start Hydras 3LT. Wait for Hydras 3LT to establish communications with the sensor.
Click the OPERATE SONDE button.
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Rhodamine WT Sensor
3. Click the Calibration tab and select Rhodamine ppb.
4. Place the sensor into a 0 ppb baseline solution. Enter zero in the
Rhodamine ppb field.
5. Press CALIBRATE. "Calibrate Successful!" screen will be displayed.
6. Place the sensor into a known ppb solution or use the Solid Standard. Enter the
rhodamine value in the Rhodamine ppb field.
7. Press CALIBRATE. A "Calibrate Successful!" screen will be displayed.
Method 2
Note: Voltage values for zero and non-zero ppb rhodamine samples are similar between different
sensors, but not identical. When using Method 2, every sensor will have a unique voltage value for a
given concentration.
Use this method when you have voltage values for both a "zero" and "non-zero" ppb
rhodamine sample. Typically, both zero and non-zero samples are measured using the
sensor to get voltages and then the same samples are measured using a calibrated
laboratory fluorometer to get "true" values for the rhodamine concentration.
1. Connect the sensor to a PC.
2. Start Hydras 3LT. Wait for Hydras 3LT to establish communications with the sensor.
Click the OPERATE SONDE button.
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Rhodamine WT Sensor
3. Click the Calibration tab and select Rhodamine Volts.
4. Enter zero into the Rhodamine ppb field.
5. Enter the corresponding voltage into the Voltage field.
6. Press CALIBRATE. A "Calibrate Successful!" screen will be displayed.
7. Enter the non-zero value into the Rhodamine ppb field.
8. Enter the corresponding voltage into the Voltage field.
9. Press CALIBRATE. A "Calibrate Successful!" screen will be displayed.
Calibration Performance Check
The optional Solid Standard can be used as a calibration performance check. The Solid
Standard can establish a correlation between a know concentration found from laboratory
measurement of a sample whose signal output voltage from the Rhodamine WT sensor is
also known. The Solid Standard can also be used to check the sensor stability periodically.
The Solid Standard is a solid fluorescent device placed over the optical head. A flat head
screwdriver is used to adjust the magnitude of the fluorescent response from 0 to
approximately 1000 ppb. The Solid Standard can be used to establish a correlation
between a known concentration and the fluorometer output voltage. It can also be used to
check the sensors stability and/or check for the effects of bio-fouling.
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Rhodamine WT Sensor
Using the Solid Standard
Note: Solid Standards give unique responses for a given sensor. A given setting on a Solid Standard
should only be used for the sensor on which it was calibrated.
1. Make sure the optical surface of the sensor is clean and dry.
2. Immerse the sensor into a known Rhodamine WT dye solution. Note the sensor
output voltage.
3. Clean and dry off the sensor. Place the Solid Standard on the optical end of the sensor.
4. Rotate until the Solid Standard is properly aligned with the indexing mark on the sensor.
A "clicking" noise will be heard when aligned properly.
5. Adjust the Solid Standard to produce the same output voltage from the sensor as in step
two. Use the provided screwdriver to adjust the screw located on the side of the cube.
Adjust the screw clockwise to increase the signal, and counter-clockwise to decrease
the signal.
6. For future use, this Solid Standard can be used as a verification device for this sensor.
Specifications
Specifications are subject to change without notice.
Minimum Detection Limit
Dynamic Range
0.1 ppb
Low sensitivity: 0–1000 ppb; Medium Sensitivity: 0–100 ppb; High Sensitivity: 0–10 ppb
Linearity 0.99 R 2
Resolution
Range
Accuracy 1
Resolution
Warranty
0.01 ppb
0–1000 ppb
± 3% of reading or ± 0.1 ppb, whichever is greater
0.01 ppb
The sensor is covered by a one-year warranty.
1 The following exceptions are taken to the specified accuracy under IEC 1000-4-3:1996: Vertically-oriented radiated
interference of 10V/m between 20 and 600 MHz has been observed to cause measurement shifts up to 5V (with
corresponding shifts in the analyte reading) when the Sonde with this sensor was exposed to the stated field.
Horizontally-oriented radiation interferences of 10V/m between 50 and 150 MHz and between 450 and 600 MHz has been
observed to cause measurement shifts up to 140 mV (with corresponding shifts in the analyte reading) when the Sonde with
this sensor was exposed to the stated field. Radiated interference testing was performed in air. Normal operation of the Sonde
under water is expected to decrease the impact of the radiation interference.
Accessories
Description
Cat. No.
Solid Standard 007205
Dye-Rhodamine, 8 oz. 21.33% ± 2.5% (w/w) 007273
© Hach Company, 2004-2005. All rights reserved. Printed in the U.S.A. ce/dk 08 February 2005 Edition 3